Yogurt starter cultures
Yogurt starter cultures suppliers and sourcing guide
Yogurt starter cultures are blends of Lactobacillus delbrueckii subsp. bulgaricus and Streptococcus thermophilus, the two thermophilic lactic acid bacteria that ferment milk into yogurt; many blends add strains such as L. acidophilus or bifidobacteria. Culture houses grow the strains separately, then blend and supply them as frozen pellets or freeze-dried powder for direct-to-vat use, sized in units per volume of milk. Blends are chosen for acidification speed, texture, mildness and post-acidification.
- Category
- Probiotics, cultures and yeasts
- Also known as
- yogurt culture · thermophilic starter culture · Streptococcus thermophilus and Lactobacillus bulgaricus · DVS yogurt culture
- Facts checked
- November 2026
Forms and grades of yogurt starter cultures
Suppliers sell different products under the same name. Specify the one you need.
Freeze-dried direct-to-vat
Sachets sized in units for a stated volume of milk, stored frozen or refrigerated and added straight to the vat.
Frozen direct-to-vat pellets
Frozen concentrated culture for larger plants, stored deep-frozen.
Bulk starter
Mother culture propagated in the plant before inoculating the vat.
Blends with added strains
Starter plus strains such as L. acidophilus or B. animalis subsp. lactis, with a count for each added strain.
Plant-based cultures
Blends selected to ferment soy, oat, almond or coconut bases, sometimes with added sugars the culture needs.
What to check on the COA
Compare each result with your own specification when the lot arrives.
- Count by species
- S. thermophilus on M17 agar and L. bulgaricus on acidified MRS agar, reported separately, plus counts for any added strains.
- Acidification activity
- Time to reach a set pH in standard milk at a stated temperature, the culture house's measure of how fast the lot will work in the vat.
- Phage profile
- The culture's rotation group and the supplier's phage-resistance information, used to plan culture rotation in the plant.
- Contaminant microbiology
- Coliforms or Enterobacteriaceae, E. coli, Staphylococcus aureus, yeast and mold, and absence of Salmonella and Listeria monocytogenes.
- Allergen statement
- Declaration of milk, soy or other allergens used in the growth medium or carrier, which buyers need for their own label review.
Storage, lots and expiry
Storage and shelf life
Frozen direct-to-vat pellets are kept deep-frozen at the temperature the supplier specifies (often -45 °C or colder), and freeze-dried sachets frozen or refrigerated, in sealed foil packs. Take out only what goes into the batch and do not refreeze thawed pellets or reseal partly used sachets for long. Shelf life is set by the supplier from activity and count data at the stated storage temperature.
Lots and expiry dates
Record the units or CFU, the activity test result and the culture's code for each lot, and keep the culture lot traceable to finished batches. Culture houses group strains into rotation sets to manage bacteriophage, so follow the supplier's rotation scheme and rotate stock FEFO.
Regulatory status
Facts from regulators and standards bodies, each linked to its source.
21 CFR 131.200 defines yogurt as milk cultured with a characterizing bacterial culture containing Lactobacillus delbrueckii subsp. bulgaricus and Streptococcus thermophilus.
Source: ecfr.gov (opens in a new tab)21 CFR 131.200 allows yogurt to be treated after culturing to inactivate viable microorganisms, to extend shelf life.
Source: ecfr.gov (opens in a new tab)The EU Novel Food Catalogue gives Streptococcus thermophilus (POL-NF-09460) and Lactobacillus bulgaricus (POL-NF-09439) the status not novel in food, as bacteria used as characteristic ingredients in fermented foods.
Source: ec.europa.eu (opens in a new tab)
This is general information, not regulatory advice. Status differs by country and by how the ingredient is used, so check the rules for your product and market.
Yogurt starter cultures suppliers
Manufacturers and distributors whose own websites say they sell it.
We are checking yogurt starter cultures suppliers now
Every listing is checked against the supplier’s own website before it goes live, so this list fills in over the coming weeks. The specs and COA checklist above are ready today.
Sell yogurt starter cultures? Request a listingFrequently asked questions
What forms of yogurt starter cultures can brands buy?
Common forms include freeze-dried direct-to-vat, frozen direct-to-vat pellets, bulk starter, blends with added strains and plant-based cultures. Ask each supplier for the specification sheet of the exact grade they quote.
What should the COA for yogurt starter cultures include?
Expect count by species, acidification activity, phage profile, contaminant microbiology and allergen statement, each with its method, specification and result for that lot.
How should yogurt starter cultures be stored?
Frozen direct-to-vat pellets are kept deep-frozen at the temperature the supplier specifies (often -45 °C or colder), and freeze-dried sachets frozen or refrigerated, in sealed foil packs. Take out only what goes into the batch and do not refreeze thawed pellets or reseal partly used sachets for long. Shelf life is set by the supplier from activity and count data at the stated storage temperature.
What is the regulatory status of yogurt starter cultures?
21 CFR 131.200 defines yogurt as milk cultured with a characterizing bacterial culture containing Lactobacillus delbrueckii subsp. bulgaricus and Streptococcus thermophilus. 21 CFR 131.200 allows yogurt to be treated after culturing to inactivate viable microorganisms, to extend shelf life. The EU Novel Food Catalogue gives Streptococcus thermophilus (POL-NF-09460) and Lactobacillus bulgaricus (POL-NF-09439) the status not novel in food, as bacteria used as characteristic ingredients in fermented foods.
More probiotics, cultures and yeasts
- Lactobacillus acidophilusL. acidophilus · acidophilus
- Lacticaseibacillus rhamnosusLactobacillus rhamnosus · L. rhamnosus
- Lactiplantibacillus plantarumLactobacillus plantarum · L. plantarum
- Lacticaseibacillus caseiLactobacillus casei · L. casei
- Lacticaseibacillus paracaseiLactobacillus paracasei · Lactobacillus casei subsp. paracasei
- Limosilactobacillus reuteriLactobacillus reuteri · L. reuteri
- Lactobacillus gasseriL. gasseri
- Limosilactobacillus fermentumLactobacillus fermentum · L. fermentum
- Ligilactobacillus salivariusLactobacillus salivarius · L. salivarius
- Lactobacillus helveticusL. helveticus
- Lactobacillus crispatusL. crispatus
- Lactobacillus delbrueckii subsp. bulgaricusLactobacillus bulgaricus · L. bulgaricus
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